Narrow Results

We tested the efficacy of 4 local agents for protection against tumor growth after tumor contamination and tumor bloc inoculation. Tumors were prepared by injecting human HT-1080 fibrosarcoma cells into the subcutaneous tissue of 6–9 week old male athymic nude mice (BALB/c nu/nu). When the tumors reached the desired size, the nude mice were sacrificed, and the tumors were harvested en bloc. Then the tumors were used in either contamination group or tumor inoculation group. In the contamination group, 34 tumors were cut by Gigli saw (Group G) and 35 tumors were cut by No. 11 scalpel (Group S). The cut surface of the tumor was rubbed into the subcutaneous tissues of non-tumor bearing nude mice for 10 seconds. Then, the nude mice from the S and G groups were randomized into either one of five subgroups: groups S–N and G–N: no local agent was used, groups S–S and G–S: lavage by saline, groups S–P and G–P: lavage by povidone iodine 10%, groups S–H and G–H: lavage by hydrogen peroxide 3%, groups S–C and G–C: lavage by cisplatin and distilled water. In the tumor inoculation group, a tumor weight of 100 mg was inoculated into 32 non-tumor bearing nude mice. Then, the nude mice were randomized into either of 5 subgroups: group B–N: no local agent was used, group B–S: lavage by saline, group B–P: lavage by povidone iodine 10%, group B–H: lavage by hydrogen peroxide, group B–C: lavage by cisplatin and distilled water. For lavage, the fluid was kept in the wound for 5 minutes apart from the cisplatin which was kept in the wound for 2.5 minutes and then the wound was filled with distilled water for the next 2.5 minutes. Tumor growth occurred in S–N, S–S, S–H, S–P and S–C groups in 33.3%, 67.7%, 16.7%, 16.7%, and 0% respectively. Tumor growth occurred in G–N, G–S, G–H, G–P, and G–C groups in 50%, 67.7%, 33.3%, 33.3%, and 0%, respectively. The total growth incidence after tumor contamination in the no-agent, saline, hydrogen peroxide, povidone iodine and cisplatin groups were 41.7%, 58.3%, 25%, 25% and 0%, respectively. Growth occurred in 100% of B–N and B–S groups, 83% of B–H and B–P groups and 33.3% of the B–C group. Cisplatin used for 2.5 minutes followed by distilled water for 2.5 minutes is effective for protection against local tumor recurrence due to tumor contamination. It also has a reasonable effect against tumor blocks.